package/gcc/4.9.4/873-xtensa-fix-_Unwind_GetCFA.patch

   1 From 15c7c4d39b317f0d902ef28fd43eca5c3369f891 Mon Sep 17 00:00:00 2001
   2 From: Max Filippov <jcmvbkbc@gmail.com>
   3 Date: Sat, 15 Aug 2015 05:12:11 +0300
   4 Subject: [PATCH 3/3] xtensa: fix _Unwind_GetCFA
   5
   6 Returning context->cfa in _Unwind_GetCFA makes CFA point one stack frame
   7 higher than what was actually used by code at context->ra. This results
   8 in invalid CFA value in signal frames and premature unwinding completion
   9 in forced unwinding used by uClibc NPTL thread cancellation.
  10 Returning context->sp from _Unwind_GetCFA makes all CFA values valid and
  11 matching code that used them.
  12
  13 2015-08-18  Max Filippov  <jcmvbkbc@gmail.com>
  14 libgcc/
  15         * config/xtensa/unwind-dw2-xtensa.c (_Unwind_GetCFA): Return
  16         context->sp instead of context->cfa.
  17
  18 Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
  19 ---
  20 Backported from: r226964
  21
  22  libgcc/config/xtensa/unwind-dw2-xtensa.c | 2 +-
  23  1 file changed, 1 insertion(+), 1 deletion(-)
  24
  25 diff --git a/libgcc/config/xtensa/unwind-dw2-xtensa.c b/libgcc/config/xtensa/unwind-dw2-xtensa.c
  26 index 35f7797..ef6b900 100644
  27 --- a/libgcc/config/xtensa/unwind-dw2-xtensa.c
  28 +++ b/libgcc/config/xtensa/unwind-dw2-xtensa.c
  29 @@ -130,7 +130,7 @@ _Unwind_GetGR (struct _Unwind_Context *context, int index)
  30  _Unwind_Word
  31  _Unwind_GetCFA (struct _Unwind_Context *context)
  32  {
  33 -  return (_Unwind_Ptr) context->cfa;
  34 +  return (_Unwind_Ptr) context->sp;
  35  }
  36
  37  /* Overwrite the saved value for register INDEX in CONTEXT with VAL.  */
  38 --
  39 1.8.1.4
  40